The present invention relates to a commercial washer for washing large quantities of commercial kitchenware and, more specifically, to a washer having improved tank features and an automated control system for automatically dispensing cleaning agent into the tank and for automatically controlling fluid turbulence and temperature in the tank to increase the effectiveness of the washer and to allow the washer to clean dishware having varied fragility.
Commercial washers have been in the marketplace for decades. Examples are shown in U.S. Pat. Nos.: 5,927,309; 5,775,347; 5,983,908; and 4,773,436, incorporated herein by reference. Many of the commercial washers that are currently on the market include multiple tanks for various cleaning stages (e.g., a scraping tank, washing tank, rinsing tank, and sanitizing tank). The washing tank, at a basic level, typically includes features such as a rectangular tank with a drain, a valve for closing the drain, outlet nozzles attached to walls of the tank for directing water down into the tank, and a pump to circulate water from within the tank into a manifold that feeds the water through the nozzles.
U.S. Pat. No. 4,773,436 discloses a tank of the variety discussed above. That patent discloses placing the nozzles on the rear wall and the pump intake valve on a sidewall. The nozzles are directed downwardly into the tank to direct water against the bottom wall of the tank near the front wall to create a circular water flow within the tank. As is common with commercial washers on the market, the pump is a single speed pump that creates a constant level of turbulence.
A problem not satisfactorily addressed by prior art and preexisting commercial washers is that, even within the commercial environment, not all dishware is sturdy or durable. For example, most restaurants use glassware, and fancier restaurants also include china or expensive ceramic plates. Prior commercial washers of the variety disclosed in U.S. Pat. No. 4,773,436 are not satisfactory for handling more delicate dishware. Rather, such prior art systems are best suited for handling larger pots and pans that are not subject to breaking under turbulent tank conditions. Moreover, some dishes contain inordinately xe2x80x9ccaked-onxe2x80x9d food debris that requires higher turbulence than that provided for by existing commercial washers. The prior art does not provide a commercial washer with variable speeds to handle a variety of cleaning needs.
Further, the prior art commercial washers do not provide programmable cycles that enhance the cleaning process. Prior art commercial washers typically only provide an xe2x80x9conxe2x80x9d or xe2x80x9coffxe2x80x9d mode. When in the xe2x80x9conxe2x80x9d mode the washer runs at one speed (i.e., flow rate) and thus provides only one level of turbulence. It is, nonetheless, desirable to provide a tank that varies the cleaning parameters to tackle kitchenware that is more difficult to clean because food or grease has become caked-on the kitchenware during the cooking or food preparation process. The prior art systems do not, however, provide programmable controllers to provide cycles that vary the tank turbulence and/or temperature for predetermined time cycles.
Another problem associated with the prior art commercial washers is that pipes and nozzles unnecessarily extend from the side or back walls downwardly into the tank to supply water to the tank. Because most commercial washing tanks are typically full of dishware, the pipes and nozzles get in the way because they are under the surface of the water during normal operating conditions. Further, it is possible for personnel washing the dishes to catch their hands on the pipes and nozzles during the dishwashing process, thus causing injury. The pipes and nozzles also unnecessarily increase the cost of the dishwasher.
And yet another problem not solved by the prior art is the need for automatically introducing desired amounts of cleaning agent into the tank. In typical operation, a commercial washer will be used for several hours with a batch of water and a specified amount of cleaning agent (e.g., soap or intensified cleaners for tougher cleaning problems) in the water. If too much soap is added to the water, it leads to waste and xe2x80x9csoap suspension,xe2x80x9d which diminishes the ability of the soap to attack grease. Adding too much soap also increases business overhead. Adding too little soap leads to the obvious problem that the dishware is not satisfactorily cleaned and sanitized. Further, commercial soaps and detergents are almost always contained in large, heavy containers. Employees manually lifting such heavy containers to pour cleaner into the water in the tank risk serious back and related injury, not to mention that it is difficult to control the amount of cleaning agent being dispensed into the tank in this manner. The prior art does not disclose an automated cleaner dispensing system that automatically dispenses a predetermined, desired amount of cleaner into the tank when necessary.
This invention is directed to a washing device and, more specifically, to an automated commercial washing tank for washing commercial kitchenware. The automated tank comprises a tank that is adapted to hold a fluid for washing kitchenware. The washing tank also includes outlets in the tank wall. A pump system includes a pump and fluid conduit system to couple the pump between an intake opening through one of the walls and the outlets. The pump draws cleaning fluid from within the tank through the intake opening into the fluid conduit system to the outlets into the tank. In the preferred embodiment, the outlets are discharge openings that are formed as openings in at least one of the walls, and do not include pipes or nozzles.
In a more specific aspect of the invention, the tank has a bottom wall and an enclosure wall. The enclosure wall is coupled to the bottom wall and extends upwardly from the bottom wall. The enclosure wall includes an angled portion directed generally downwardly into the tank. At least some of the discharge openings are located in the angled portion. In an even more preferred embodiment, the enclosure wall includes two angled portions and a group of discharge openings located, at least in part, in each angled portion. The angled portions are preferably opposed and directed downwardly into the tank to direct cleaning fluids from the openings generally downwardly into the tank in a crossing pattern.
In another aspect of the invention, a control system is coupled to the pump for controlling the flow rate with which the pump supplies the cleaning fluid to the outlets. The control system comprises a controller coupled to the pump system for causing the pump to alter the flow rate with which it pumps fluid, and a control that is adapted to allow a user to activate the controller to select between at least two different flow rates for pumping the cleaning fluid to the outlets. In the preferred embodiment, five different flow rates are available. In an even more preferred embodiment, the controller provides at least one preset program that, when activated by the control system, automatically adjusts the pump flow rate and/or temperature in the tank for at least two predetermined cycles to enhance the cleaning effectiveness of the tank.
In another aspect of the invention, the automated washer provides an overflow that comprises a cutaway portion in one of the walls. The cutaway portion preferably extends the full length of one of the sidewalls and is located at a height above the discharge openings. The overflow is preferably located adjacent a side tank that has a drain for fluid that spills over the overflow. Because grease and other debris float, the overflow also serves to dispose the grease and floating debris from the washing tank over the overflow.
In another aspect of the invention, an automated cleaner dispensing system is provided that automatically dispenses cleaner (e.g., soap or detergent) into the fluid in the tank. In the preferred embodiment, a fluid level sensor determines when the fluid level has dropped below a desired level and detects when the fluid level is thereafter increased above the desired level, indicative that the tank has been emptied and refilled. The control system, upon detecting the low level condition and the refill condition, causes a predetermined amount of cleaner to be dispensed into the tank.
Thus, the automated dishwasher disclosed herein overcomes problems associated with the prior art. The use of discharge openings for directing cleaning fluid in the tank eliminates the need for pipes and nozzles to do so. Thus, the nuisance of having the pipes and nozzles in the tank is eliminated and the overall cost of the dishwasher is decreased. Further, by providing outlets on more than one wall, and preferably opposed walls, tank turbulence is increased, thereby enhancing the washer""s effectiveness in cleaning kitchenware. The control system aspect of the invention allows the pump pressure to be increased or decreased to account for varied conditions of kitchenware that must be cleaned. The preset program feature automates the cleaning process and also facilitates cleaning kitchenware having caked-on food by, for example, providing various cycles that can operate automatically overnight. The control system also allows for automated control of the cleaner dispenser and the heater. Thus, the dishwasher is adapted to clean all dishware, regardless of how fragile or dirty, and is much more effective and automated than prior art commercial kitchenware washers.